: Power Steering Fluid

02-15-07, 02:12 PM
I spoke with fellow CTS-V owner Doug Bruce yesterday and he noted his power steering fluid boiled at a track day last year. I did a little research into flash points of steering fluid. NOT very scientific but below are a few flash point temps from several brands. All but Red Line are traditional petroleum based fluids. I'm assuming the boiling point is higher along with a higher flash point.

F = Farenheit
C = Celcius

Pyroil (Valvoline's Low End Brand): 347F 175C
Penzoil: 365F 185C
Castrol: 350F 177C
Red Line Synthetic: 437F 225C

Some brands (STP and Valvoline Synthetic) didn't have this info published on their web sites. Oh and the viscosity at
-40C is much lower on the Red Line as well so maybe it can help elimate the squeal upon start up.

Hell of a lot easier to flush the fluid and replace with say Red Line then swap out the power steering cooler.


02-15-07, 09:49 PM
:thumbsup: Good stuff Feff!

02-15-07, 10:23 PM

Bought two quarts of the Red Line today for a quick (I hope) weekend project to go along with rear end "clunk" correction (again I hope) if Ground Control calls me back.

By the way, Red Line's web site says their power steering fluid is OK for GM systems.


02-15-07, 10:38 PM

I used Royal Purple Synthetic. I'm normally a Redline user, but I got the Royal Purple at a pretty good price and I've always considered them to be just as good. Anyway, here's the specs I have on the Royal Purple:

Flash: > 400F
Boiling Pt: 650 - 800F

They did not list a low-temp viscosity, but they do list the pour pt to be -50F. I still get the initial ps pump whine when the car has cold-soaked in single digit outside temps or below.

I'm curious how the Redline would do.


02-15-07, 10:41 PM
Thanks for the info Feff....I was asking rgd about trans oil and diff oil. Any recommendations there?

FAQ had easy replacement guide for the power steering cooler (http://www.cadillacfaq.com/faq/answers/steeringcooler/index.html) Just thought about it....would the Redline work with the stock power steering cooler just fine, or would you recommend Redline and a new power steering cooler (around $45)?



02-16-07, 12:10 AM
Perhaps it is easier than changing the cooler, but it cant be too much easier. The cooler change is an hr at best.

The only reason I bring this up is because my engine oil temp used to run at around 280-300deg as high as 330deg. After adding an oil cooler it never goes higher that 230-240deg.

I am sure its the same comparatively with the pwr steering cooler; the OEM is probably 70% less efficient than aftermarket.

Heat Kills!

my $0.02